The present invention relates generally to new and novel improvements in fluorescent security printing ribbons. More particularly, the present invention relates to thermal transfer printing ribbons capable of printing security characters and indicia in conjunction with product identification bar codes and other visible printing, such that the security characters and indicia are invisible under broad spectrum light, but fluoresce, and become visible, when exposed to black light.
One prevalent problem in the retail industry is how to verify that merchandise sold to a customer was sold by a particular store. Although the name of the store could be visibly printed on the product's packaging, or directly on the product, doing so is sometimes undesirable to consumers who, for example, may want to give the purchased products to others as gifts, or may want to use the items without visible printing. In addition, if the store name is visible, it is readily apparent and could be fraudulently reproduced by unscrupulous individuals.
Accordingly, an object of the present invention is the provision of printing ribbons capable of printing security characters and indicia incorporated into, for example, product identification bar codes or other visible printing, such that the security characters and indicia are invisible under broad spectrum light, but fluoresce, and become visible, when exposed to black light.
Another object of the present invention is the provision of printing ribbons capable of printing security characters and indicia which are transparent, and thus invisible under broad spectrum light, but which fluoresce, and become visible, when exposed to black light.
A further object of the present invention is the provision of thermal transfer printing ribbons capable of printing fluorescent security characters and indicia using conventional thermal printing equipment.
Yet another object of the present invention is the provision of thermal transfer printing ribbons capable of printing product identification bar codes and other visible images under control of a thermal transfer print head and security characters and indicia controlled, at least in part, by predetermined spot coated patterns or configurations present on the thermal transfer printing ribbons prior to the printing operation.
These and other objects of the present invention are attained by the provision of printing ribbons consisting of elongated backing elements with printing media adhered to one side thereof. The printing media is preferably capable of being transferred to paper, or some other print receiving media, by conventional thermal transfer printing equipment. In one preferred embodiment, the thermally transferred printing media includes a uniform interspersed distribution of fluorescent pigments, resulting in printed security characters and images which are transparent, and thus invisible, under broad spectrum light, but which fluoresce, and become visible, when exposed to black light. In a second preferred embodiment, the thermally transferred printing media includes a uniform interspersed distribution of visible black or colored pigments, as well as fluorescent pigments, resulting in printed product identification bar codes or other visible printed images which are visible under broad spectrum light, as well as printed security characters and indicia which are transparent, and thus invisible, under broad spectrum light, but which fluoresce, and become visible, when exposed to black light. If desired, the visible printed images or patterns can be made in one configuration, for example, conventional product identification bar codes, controlled by the thermal print head and the fluorescent security characters and indicia can be made in a different configuration, for example, the name of a particular store, or the store's logo, controlled, at least in part, by predetermined spot coated patterns or configurations present on the thermal printing ribbons prior to the printing operation. Thus, printing ribbons in accordance with this invention can be used to print visibly transparent printing, black printing, or other color printing as viewed under broad spectrum light, and independent fluorescent security characters and indicia which are invisible under broad spectrum light, but which fluoresce, and become visible, when exposed to black light.
Other objects, advantages and novel features of the present invention will become apparent in the following detailed description of the invention when considered in conjunction with the accompanying drawings.